exam 3 Flashcards
what animal can we harvest milk from?
any animal
what animal produces the most fluid milk?
cows
what percent of fluid milk do cows produce?
90%
during what time period did dairy consumption increase?
1940s to present
how many dairies produce 85% of milk product?
less than 100
less than 100 cow diaries produce what percentage of milk product?
85%
what percent of dairy products is fluid milk?
45%
what percent of fat is skim milk?
0.5%
what percent of fat is homogenized/whole milk?
3.5%
what is another term for whole milk?
homogenized
what percent of fat is half and half?
12-15%
what percent of fat is low fat milk?
1-2%
what percent of fat is whipping cream?
20-30%
what percentage of dairy products is fermented/frozen (cheese, butter, yogurt, etc.)?
55%
what is happening to fluid milk consumption?
going down
what are some examples of goat cheeses?
romano, provolone, blue
what are some examples of sheep cheeses?
feta, manchego, roquefort
what % fat content is in human milk?
3.7%
what % fat content is in cow milk?
4.0%
what % fat content is in goat milk?
4.1%
what does pasteurization do?
destroy potential pathogens in milk
what does homogenization do?
breaks fat molecules into microscopic pieces
what percentage of fat is in ice cream?
12-15%
what are cheeses high in?
fat
what is the fat % in cheese?
30-50%
what percentage of fat is ice milk?
3-7%
what percentage of fat is butter?
70-80%
what is the difference between grazing and browsing?
grazing is primarily forages/grasses while browsing is a wider variety
what are the five major dairy breeds?
ayrshire, brown swiss, guernsey, holstein, and jersey
where are ayrshire cows from?
scotland
what are characteristics of guernsey cattle?
average- 15000 lbs of milk produced; ~5% fat; orange milk
what are guernsey cattle developed for?
cheese production
why would milk be orange?
has concentrates of carotenes in milk
what are characteristics of holstein cattle?
average- 25000 lbs of milk produced; ~3.5% fat
where are holstein cattle from?
the netherlands
what are jersey cattle known for?
butter
where are jersey cattle from?
isle of jersey
what is the fat percentage is in milk from jersey cattle?
5%
what is the past and current breed distribution of dairy cattle?
used to be more mixed breeds but now 90% holsteins
why are most dairy cattle holstein?
producers are paid for lbs of milk, fat and protein content and holstein is easily the highest producers of each
what is an agricultural cooperative?
legalized monopoly
what do milk grades indicate?
milk quality/sanitation parameters
what grade are 90% of dairies?
grade A
what two sanitation parameters determine milk grade?
somatic cell count and bacteria level
what products can grade A be used for?
any dairy products
what products can grade B milk be used for?
processed products (not fluid milk)
what guidelines must grade A milk follow?
must cool to 45% within 2 hrs and follow water body authority standards
what are the four classes of dairy?
I. fluid
II. soft products
III. cheese
IV. butter
what does pasteurization change in regards to consumption?
greatly changes taste
what is the calving interval?
12 months
what is the economic threshold?
$ return required to meet $ cost
what is stripping?
stripping of potential bacterial infections
how can milking be expedited?
changing how fast you can get the cows in and out of milking- milking time does not change
what is genetic selection doing?
selecting parents of the next generation
what is heritability?
proportion of a trait passed from parent to offspring through genetics
how is genetic selection done in dairy?
artificial insemination with excellent records of performance
what are sire summaries?
prediction of daughter’s performance
what does it mean if a sire summary says +1805 lbs of milk?
you can expect the daughter of this sire to produce 1805 lbs of milk per lactation compared to breed average
what are the two things you must know when looking at a sire summary?
- average for breed of traits
- your herd average for that trait
why is the herd average for a trait important?
to determine the actual effect on your herd
how successful is sexing semen?
60-80% average
what is the difference between an X sperm and a Y sperm?
X has more volume and is slower and Y sperm has less volume and is faster; X is more negative because it has more DNA and Y is more positive because it has less
how are sperm sorted by sex?
based off electric charge
what does BST stand for?
bovine somatropin
what is bovine somatropin?
bovine growth hormone that is naturally occurring, major regulator of milk production, increases metabolic rate and lipolysis
what was the state of BST use in 2005?
17.2% of cows received BST resulting in a 6-8% increase in feed intake and a 10-20% increase in milk production
what was the state of BST use as of 207?
not used because of social pressure
how much does sheeps milk cost in relation to cow?
4x
what are mammary glands?
milk producing organs
what is an udder?
connected mammary glands via connective tissues
how many mammary glads do cows have?
4
what is the general rule regarding number of mammary glands?
2x the average number of offspring
what is a dry lot?
where non-milking cows go that will calve within 60 days
why are animals removed from milking ~60 days prior to calving?
udder involution to maximize production during the next lactation
what is freshening?
common term for animal following parturition
what is milk fever called?
hypocalcemia
what is the cause of milk fever?
calcium requirement for milk exceeds demineralization rate which results in insufficient levels needed for muscle/ nerve function
what is the treatment for milk fever?
calcium administration
what is the primary objective of the calf barn?
to raise the calf
what happens in the calf barn
harvest the milk for human consumption; significantly habituates animals to human presence; calves removed immediately following birth
what is passive immunity?
direct transfer of antibodies
what are some aspects of dairy calf management?
isolate to minimize disease spread; provide access to water, feed, and hay; provide milk or milk replacer; dehorning, vaccinations, castration; weaning; puberty; bred to calve at two years old; following calving, heifer will enter milking string
what are the two primary milking units?
pneumatic driving teat cups of the claw and ankle bracelets to ID the animal and results in monitoring lbs of milk produced
what is milk stored in?
a bull tank
what is the general milking procedure?
- wash teats
- teat drip
- stripping
- apply claw
- teat dip
what is the traditional milk frequency? (hrs)
12 hours
what is the milking frequency to reach peak intramammary pressure and decrease milk synthesis?
6 hours
what is the milking frequency more commonly found on large, commercial dairies?
8 hour intervals
why are 8 hour milking intervals most commonly used?
allow for greater milk production and work better with traditional 8 hr working shifts
what is mastitis?
inflammation of the mammary gland
what is the most common cause of mastitis?
bacteria entering streak canal
how is mastitis identified?
fever, depression, loss of appetite, change in behavior; milk: flakes, clouding blood, clumps
what are CMT or other antibody agglutination tests used for?
helps identify sub clinical cases of mastitis before they become major problems
what is the usual treatment of mastitis?
direct infusion of antibiotics into mammary gland
what are grades of milk based on?
somatic cell count (indirect measure of facility sanitation) and animal health
what happens to milk production during the first trimester?
maximum milk production
what happens to milk production during the second trimester?
milk production decreases
what happens to milk production during the second trimester?
more linear decrease in milk production following 2nd tri
what happens to milk production during the second trimester?
cows are dry 60 days prior to calving
what number of lactations is considered peak production?
3 to 6
what number of lactations is considered typical production?
7 to 8
what is non-seasonal polyestrous?
estrous cycles year round (minimizing calving season)
what are the benefits and negatives of spring calving?
+ nutrition
+ weather
- value (supply and demand)
what are the benefits and negatives of spring calving?
+/- nutrition
+/- weather
+ value (less supply = more demand)
when does weaning happen?
5 to 7 months / 400-600lbs
what happens during spring work in spring calving?
branding, dehorning, castration, vaccinations, etc.
what happens to offspring that is kept after fall work?
they become replacement females
what cows are the hardest and easiest to breed?
virgin heifers are the easiest and 1st calf heifers are the hardest
why are first calf heifers the hardest to breed?
they are still growing, lactation, and uterine involution
what are the top three grades of meat?
prime, choice and select
what are the characteristics of prime grade meat?
young cattle with more intramuscular fat
what are the characteristics of choice grade meat?
young cattle with moderate intramuscular fat
what are the characteristics of select grade meat?
young cattle with some intramuscular fat
what are the primary retail cuts?
chuck, rib, loin, and round
what is yield grade?
amount of primary meat cuts from a carcass
what does a 1 yield grade entail?
more product/carcass; more primary cuts, less fat
what does yield grade 5 entail?
less product/carcass, less primary cuts, more fat
what is the estrous cycle of a cow?
21 days
how long is estrus of a cow?
12 hours
how long is cattle gestation?
285 days
why are wagyu unique?
they have extreme marbling/ intramuscular fat
what kind of relationship does quality have with yield grades?
inverse relationship
what is optimal meat grade and yield grade?
choice + 2.5
